I was surprised as that was the first time I had seen officially...

I was surprised as that was the first time I had seen officially the IP spec and it was only for dust. Doesn't mean it isn't and that they just didn't do rating? but just a red flag. I still haven't seen a set in person to fully check it out but they must breathe to compensate fr air expanding and contracting as brake heat cycles in use and they must retain a lot of heat in large downhills and rely on whole diff housing and hub act as a heatsink as plastic shell won't.

As for front and rear when the front take greater % braking capacity and you want all similar components I see it as a issue . If you can justify ecconomically them on one axel surely same for other.?

Vehicles moving in water is rarely a problem as you would know ( yes hot diffs if not remote vented etc can suck in water ) as there is little to no pressure . It is when you stop or are at very low speed wading at axle depth that the problem arises. So at a Canadian mine mid winter you wade a creek and pull up for 4 hours. What if you stop in water? End up with a lump of ice in enclosed brake if water got in? That is why I liked oil wet brakes. Salt water beach work does the breather allow in salt mist with cycling hot and cold brakes? I have assumed that they connect to diff breather and it is raised above wading height and realistically it is rare on site to go through anything greater than 12-18 inches deep let alone stop in it.

I hope newer management can keep it alive and for shareholder actually make it perform as it is a good product but never properly promoted etc etc. I expect that shareholders will get diluted to the crapper some more and when the product gets scale and traction it will be taken out cheaply as it needs large scale to economically marketed and produced IMO. I wonder if this is a strategy to make it look good and accept a buy out by a company that can leverage ?

I have never had a serious explanation of why trials on mining transport trucks never went on to sales as you can't find equipment used harder and needing uptime but it may have come down to not wanting to deal with a company on it's knees.

Any ideas on expected margins at volume levels?

It is just so hard for a small company unsupported to service the world IMO as you need deep pockets and margins.

I still don't know the possible market size that can actually get a reasonable payback period as examples used really are extreme. Extreme is a small market size.